California's Attorney General is taking action to control the skyrocketing cost of insulin. A Rob Bonta announced a lawsuit, accusing the nation's largest insulin makers of unlawfully driving up the cost of the lifesaving drug. The AG alleges manufacturers Eli Lilly, Novo Nordisk, and Sanofi, and pharmacy benefit managers CVS Caremark, Express Scripts, and OptumRx, have leveraged their market power to overcharge patients. Bonta says those three manufacturers produce over 90-percent of the global insulin supply and the three PBMs administer benefits for roughly 80-percent of prescription claims managed. The lawsuit argues that because competition is highly limited in both their markets, the six companies are able to aggressively hike the price of insulin. More than three-million adults in California have been diagnosed with diabetes.